about being aware of your environment. if you looks unusual, tell someone about it. >> reporter: best advice, don't let them affect your life. go back and live your life. >> live your life. when you compromise how you live that gives them a victory. as painful as it is to day. you can't let them succeed by us changing the norm and how we live. can't let them win. no victories. >> reporter: david kerley, abc news, washington. >> i think that last point is so important. you can't let them win. you can't say i'm not going to go to that ball game because, what if? that's exactly what they want. >> that's what they want. they want to you watch the coverage incessantly and be too scared to do anything. you have to go out, have you to live your lives. important clues, for as chaotic as that looks, there are important clues of what was left behind at these bombings that police are also looking at. the injured. they want to know if anybody has hand injuries. someone that could be potentially using bomb-making material and they have